1. Field of the Invention
The present invention relates to the field of reverse osmosis filters and dispensing valves therefor.
2. Prior Art
Reverse osmosis water filters (hereafter simply water filters) are well known in the prior art. For consumer use, such water filters generally fall into two forms, specifically, above counter water filters and under counter or under sink water filters (hereafter under the counter water filters).
The prior art above counter water filters generally have a tap water connection to the water faucet on the sink for providing tap water thereto at water line pressure, and a drain running to the sink for disposal of waste water. The accumulation of product water in such water filters is in an unpressurized container, normally part of the above counter water filter, with a dispenser formed as part of the overall assembly for dispensing product water.
The prior art under the counter water filters are normally of the type including a product water container with a diaphragm therein for receiving product water as it is produced, and a control valve that includes the capability of providing squeeze water, that is water at the water line pressure, to the outer wall of the diaphragm to pressurize product water for dispensing purposes. It is this pressurized dispensing which is most convenient for under counter usage, though as an alternative, one could use an electric pump for pressurizing the product water for dispensing, though such an arrangement becomes rather complex to prevent overflow of product water, etc. Also, in some homes, particularly in developing countries, there may not be electric power available under the counter or under the sink.
Recently, a reverse osmosis water filter has been developed which is suitable for use in both above the counter and under the counter installations. Such versatile water filters are disclosed in U.S. Pat. No. 7,601,256. The advantage of such water filters is that the same water filter may initially be used in an above the counter installation as a trial usage, and when later desired, the same unit may be placed under the counter as a more permanent and out of the way placement. Therefore, in that regard, initial placement under the counter is obviously possible, though such placement becomes a rather permanent placement in the sense that it would require special connections to the water system (pressurized tap water and drain) as well as the creation of a hole in the counter for the above counter dispensing valve. Accordingly, such permanent installation is particularly unattractive to water filter users that want to evaluate a water filter before such permanent installation.